Interfacial oxygen vacancies enhanced Zn0.4Cd0.6S/ TiO2 S-scheme heterojunction for photocatalytic H2 production

Accelerating charge transport and avoiding recombination are promising strategies for establishing highly efficient artificial photosystems. Herein, an S-scheme heterostructure consisting of Zn x Cd 1− x S and TiO 2 is fabricated via the in situ crystal growth method. The refined structure significantly enhances the transport of photogenerated charges, thereby improving photocatalytic hydrogen production efficiency. The optimized TiO 2 −Zn x Cd 1− x S composite, incorporating 60% TiO 2 with Zn 0.4 Cd 0.6 S, exhibits a robust H 2 evolution rate of 50.96 mmol g −1 h −1 with continuous release of H 2 bubbles. It is worth noting that the hydrogen production rate in seawater is as high as 26.22 mmol g −1 h −1 . The strong interfacial interaction and staggered band alignment between TiO 2 and Zn x Cd 1− x S result in the formation of a built-in electric field and high-content oxygen vacancies , which can drive the directional migration of photoelectrons with high redox ability and high speed. The designed photocatalyst with S-scheme and rich Oxygen vacancies at the interface provides a new approach for fabricating high-efficiency photocatalysts. • Ingenious structure brings intimate contact to construct fast charge transfer channel. • S-scheme heterojunction and interfacial oxygen vacancies synergistically promote photocatalytic efficiency. • The synergies between semiconductors and the conduction paths of photogenerated charges are revealed.